std::jthread::hardware_concurrency

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< cpp‎ | thread‎ | jthread

 
C++
 
Concurrency support library
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std::jthread
 
[[nodiscard]] static unsigned int hardware_concurrency() noexcept;
 (since C++20)

Returns the number of concurrent threads supported by the implementation. The value should be considered only a hint.

Parameters

(none)

Return value

Number of concurrent threads supported. If the value is not well defined or not computable, returns ​0​.

Example

Run this code
#include <iostream>
#include <thread>
 
int main() {
    unsigned int n = std::jthread::hardware_concurrency();
    std::cout << n << " concurrent threads are supported.\n";
}

Possible output: 

4 concurrent threads are supported.

See also

(C++17)
 min offset to avoid false sharing
max offset to promote true sharing
(constant)
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